Adjustable toggle pliers



Aug. 8, 1950 B.'PEPPERDINE 2,518,173 ADJUSTABLE TOGGLE PLIER S Filed May 25, 1945 v 2 Sheets-Sheet 1 INVENTOR. 551v PEPPEEQl/VE,

- B. PEPPERDINE Aug. 8, 1950 Filed May 25, 1945 ADJUSTABLE TOGGLE PLIERS 2 Sheets-Sheet 2 INVENTOR.

52w e'p seag/vg Patented Aug. 8, 1950 IED S TAT ES PAT EN T OFFICE ADJUSTABLE TOGGLE FIJIERS Ben Pei l erdine, Los Angeles, Qalifl, .assigncr to The :Plomb Tool Gompany, Los Angeles, Calif a corporation or California Application May 25, 1945, Serial No.595,796

7 Claims.

This inventionrelates generally to pliers and more particularly to "the type known as toggle pliers from the fact that such pliers have pivoted handles connected bylinks or toggles.

It is the general purpose oftoggle pliers to supplement the leverage which can be applied to the jaws of the tool. Also in some forms of holding tool akin to pliers, the toggles are arranged to reach or pass a dead center at the .point of maXimum-closure-of the jaws, by which they effect what maybe called-a clamping lock or vise and take the strain transmitted through the jaws, thereby relieving the operator'from the necessity of continuing to squeeze the handles. However, as this action takes place at a fixed point, such tools are adapted for holding articles of only one predetermined size. Special forms and arrangements of jaws and sometimes a movable pivot for the jaws have been used for overcoming this limitation, but unless the jaw pivot is continuously movable during the clamping action, the tools are still limited to certain fixed sizes and cannot grasp articles of intermediate size. If the jaw pivot is continuously movable it exposes the article held to a grinding action.

It is the generalobject of thisinvention to provide toggle pliers which have the advantages of added leverage and a clamping lock combined with adjustability over a considerable range of articles to beheld.

Another important object is to provide pliers in which the jaws may be gently closed on an article and the clamping lock applied without further closing of the jaws, thus avoiding the crushing of fragile articles.

Yet another object is to provide high leverage pliers in which the pressure-exerted by the jaws coincidentally with the clamping lock may be adjustably increased or diminished.

It is a further object to provide these advantages in pliers having the usual type of jaws, with single pivot non-grinding motion, and of sturdy construction.

In carrying out these objectives I have utilized jaws and handles of conventional shape, as the pliers are intended for ordinary use, and convenience has long stabilized the general design of such tools. One jaw fits into a groove in the other in a manner calculated to minimize side motion. As is usual with toggle tools, the jaws extend rearwardly of their common pivot without crossing, and are symmetrically hinged to handles which in turnare symmetrical and conventional in that portion to be gripped by the zoperator.

The added leverage and the'clamping lock are achieved by a toggle :having two arms extending from the handles in fixed angular relation and pivoted at their junction on a pin which makes a fulcrum common to both handles. As the handles close, the fulcrum advances, and the toggle arms force the hingedends'of the handles apart, closing the jaws. As the fulcrum approaches the line connecting the hinges, the leverage approaches a maximum, and when it reaches that line, the jaws are at their closest approach and the toggles take the inwardthrust of the hinges, relieving the handles of strain and imposing what I-have called the clamping look. It will be seen that in such a device as so far described the position of the fulcrumcontrols the set of the jaws, the amount of leverage, and theclamping lock, and that the position-of the fulcrum is in turn controlled by the position of the handles to which it is attached by the toggle arms, I- have provided means for making the position of the fulcrum variable with reference to the position of the handles, by moving the'point at whichone of the toggle arms connects with its respective handle to a location more convenient than the hinge of the handle and by installing at that convenient point means for adjusting the length of the toggle arm. In so doing Ihave made the set of the jaws, the amount of leverage, and the clamping look also variablewith respect to the position of the handles and have thereby achieved flexibility and adaptability of operation heretofore unknown in such a tool.

These various features and accomplishments of my invention, as well=as other objects not preliminarily mentioned, will be set forth in the fol lowing detailed description of a present preferred illustrative embodiment of the invention,

reference for this purpose being had to the accompanying drawings, in which:

Figure l is a side elevation of an embodiment of my invention, from the side bearing the aforesaid adjustable toggle arm, and with certain hidden pivot points shown in dotted lines;

Figure 2 is "a plan view of the pliers as they --grip an article but with the handles and toggle just approaching the clamping position;

Figure 3 is a view similar to Fig. 2, but showing the handles and toggle now moved to clamp the jaws upon the article; and

Figure 4 is an enlarged sectional .view of the head of the pliers as shown in Fig. 2.

In the drawings the numeral H3 designates the male jaw of the pliers, the rearward inner .por-

tion of which is cut away on both sidestto iorzn amps it central rib II. The female jaw I2 has a central groove between side flanges I3 to receive the rib II, the flanges and the rib being fitted closely to keep the jaws in alignment. Both the male jaw I and the female jaw I2 are pivoted on the pivot pin I4 which extends through the rib of the one and the side flanges of the other, and they carry adjacent their respective rearward ends the hinge pins I5 and I6 upon which are hinged the handles I1 and I8. The rib II follows approximately the direct line between the pivot pin I4 and the hinge pin I5, but the flanges I3 of the opposite female jaw extend rearward over the longitudinal axis of the pliers to form a rounded corner I9.

The forward end of the handle I! is widened into triangular form with rounded corners 2H and 2| and is grooved transversely in the same manner as the female jaw I2 so as to receive between the resultant fianges 22 the end of the rib II of the male jaw III to which it is attached at the outer corner 20 by the hinge pin I5. The inner corner 2I carries between its flanges a fulcrum pin 23 and is extended inwardly so as to bring the fulcrum 23 approximately on the longitudinal axis of the pliers when the adjustment, to be presently described, is in median position.

In a corresponding manner, the handle I8, which is hinged to the female jaw I2, is flattened at its forward end to the thickness of the rib I I, so that it may enter between the flanges I3 and be hinged therebetween by the hinge pin I8.

At a short distance reawardly from the hinge pin IS, the handle I8 is pierced with a threaded hole to receive a hollow adjustment screw 24 having an open end extending between the handles and a knurled head on the outside of the handle. Extending into the open inner end of the screw 24 is a swivel bolt 25, fitting the hollow core of the screw with a slide fit so as to allow relative rotational movement. The end of the bolt 25 within the core of the screw 24 has an internally threaded hole formed therein to receive a retainer screw 25 extending through a smooth-bored hole in the head end of the screw 24. The retainer screw 28 has a fillister head which seats within a counterbored recess in the knurled head of the screw 24 and its function is to confine the shank of the swivel bolt 25 within the bore in the screw 24 while permitting relative rotation between the two parts. The inner, or extruding end, of the bolt is transversely pierced with a hole to receive the fulcrum pin 23. The bolt 25 and screw 24 together form a unit of fixed length capable of being shifted axially with respect to the handle I8 to provide a toggle arm of variable effective length between the axes of the fulcrum 23 and pivot I 6.

The above described construction produces a toggle of two arms pivotally connected on the fulcrum 23, one of the arms being the head of" the handle I! between the hinge pin I5 and the fulcrum 23, and the other being the combined length of the bolt 25 and the screw 26 from the engagement of the former with the fulcrum 23 to the engagement of the latter with the handle IS. The last mentioned arm is adjustable in length and both arms are fixed in angular relation to their respective handles.

While the adjustable arm might conceivably engage the handle I8 at the hinge pin I6, I prefer the rearward location described and shown as providing a less complicated juncture and not weakening or interfering with the hinge. The

arm is thrust forward from its juncture with the handle so as to permit the fulcrum 23 to attain alignment with the hinges I5 and I6 when the handle is, in general, parallel with the axis of the pliers, the exact spread of the handles when such alignment is attained being dependent on the adjusted length of the arm.

In operation, when the jaws of the pliers grip an article and the handles are moved to tighten the grip, the fulcrum 23 moved forward, its forward movement being limited by contact of the flanges 22 at the corner 2| with the flanges I3 at the corner I9. This limited movement prevents the toggle from overshooting the alignment of the fulcrum with the hinges I5 and I6 and thus reopening the jaws. Moving the handles to release the grip moves the fulcrum rearwardly.

The leverage-advantage is gained in the manner common to gripping tools of the toggle type, in that the hinges I5 and I6 are moved apart and the jaws I0 and I2 closed by the leverage of the handles around the movable fulcrum 23, with the leverage becoming maximum as the fulcrum approaches the line of the hinges.

The adjustment screw 24 serves, among other purposes, to regulate the width of the jaws in their clamped position. Turning the screw in and thereby lengthening the toggle arm increases the maximum distance between the handle hinges and thereby decreases the minimum width of the jaw spread, and vice versa. In this way the pliers may be used to grip articles of various sizes. The adjustment screy also serves to adjust the degree of pressure with which an article is gripped when the clamping lock is applied. By turning the screw outwardly and thus shortening the toggle arm, the handles are brought closer together for any given spread of the jaws and the fulcrum 23 is further advanced. If the fulcrum is advanced nearly to the line between the hinges, a very little motion of the handles will advance it the rest of the way and thus secure a clamping lock with little motion of the jaws. When a delicate article, subject to crushing, is to be held firmly, such a feature is of great usefulness. It will be apparent that although my invention is in the form of pliers it may be adjusted like a monkey wrench to grip an article with any desired force, by placing the article between the jaws and advancing the fulcrum to the line of hinges by means of the adjustment screw while resisting the outward movement of the handles with whatever force is deemed desirable.

Where no clamping lock is desired, the pliers may be used as ordinary pliers of great jaw width by allowing the of the angle formed by the toggle arms to point rearwardly. The compound leverage of the toggle may still be used in this position, although of course not so effectively.

While I have described one preferred illustrative embodiment of my invention, it is to be understood that the invention is not limited to the exact embodiment shown and described, but that various changes may be made in design, structure, and arrangement without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. A toggle for the handles of pliers of the class described comprising a pair of arms, a fulcrum pivotally connecting the said arms, one of the said arms being carried by one of the said handles at the forward end thereof and substantially normally to the axis of the said handle, and the other of the said arms being movably supported by the other of the said handles rearwardly of the forward end thereof and at a forwardly projecting angle thereto, and an adjusting screw threadedly engaging the last-mentioned handle and engaging the last-mentioned arm with a swiveled connection.

2. Pliers, Comprising a pair of jaws; a pivot common to the said jaws; shanks on each of the said jaws extending rearwardly of the said pivot; handles pivotally connected to each of the said shanks; a toggle arm on the inner side of one of the said handles adjacent the pivoted end thereof; a fulcrum pin carried by the said arm, the said arm being adapted to project the said fulcrum pin to a position of alignment between the pivots of the said handles when the position of the handle respective thereto so permits; a portion of one of the said shanks being adapted to make contact with the said arm when the said alignment is reached and to prevent move ment of the said fulcrum substantially beyond the said alignment; a hollow screw threadedly engaging the other of the said handles at a point adjacent to and rearwardly of the pivoted end thereof and directed inwardly and forward of the said point of engagement; a swivel pin having one end rotatably engaging the said fulcrum pin and its other end with the hollow screw; and means for fastening the said swivel pin to the said hollow screw so as to cause them to move longitudinally in unison, whereby movement of the said hollow screw relative to the handle engaged thereby will vary the position of the said fulcrum pin for a given closure of the said handles.

3. Toggle pliers comprising a pair of jaws pivotally connected together intermediate their ends, a pair of handles, each pivotally connected to the end of one of said jaws, and a toggle link connection between said handles comprising a screw having threaded engagement with one of the handles, and a fulcrum pin connecting said screw to the other handle, said screw being rotatable about its longitudinal axis with respect to said fulcrum pin.

4. Toggle pliers comprising a pair of jaws pivotally connected together intermediate their ends, a pair of handles, each pivotally connected to the end of one of said jaws, and a toggle link connection between said handles comprising an arm projecting from one of the handles, a member having a fulcrum connection with said arm, and a screw threaded into the other handle and swiveled on said member, the swivel axis being coincident with the axis of said screw.

5. Toggle pliers comprising a pair of jaws pivotally connected together intermediate their ends, a pair of handles, each pivotally connected to the end of one of said jaws, and a toggle link connection between said handles comprising an arm projecting from one of the handles, a screw threaded into the other handle, said screw having a central bore formed therein, a swivel bolt confined. Within said bore, said screw being rotatable with respect to said swivel bolt, and a fulcrum connection between said swivel bolt and said arm.

6. Toggle pliers comprising a pair of jaws pivotally connected together intermediate their ends, a pair of handles, each pivotally connected to the end of one of said jaws, and :a toggle link connection between said handles comprising an arm projecting inwardly from one of said handles adjacent the pivoted end thereof, a screw threaded into the other handle at a point spaced rearwardly from its pivoted end, said screw being directed inwardly and forwardly whereby the inner end thereof approaches a line connecting the pivot points of said handles When the handles are closed, and a fulcrum pin connection between the inner ends of said screw and said arm, said screw being rotatable about its longitudinal axis with respect to said fulcrum pin.

7. Toggle pliers comprising a pair of jaws pivotally connected together intermediate their ends, a pair of handles, each pivotally connected to the end of one of said jaws, and a toggle link connection between said handles comprising an arm projecting inwardly from one of the handles, a centrally bored screw threaded into the other handle at a point spaced rearwandly from its pivoted end, said screw being directed inwardly and forwardly whereby the inner end thereof approaches a line connecting the pivot points of said handles when the handles are closed, a swivel pin having a shank portion received within the bore in said screw, a retainer screw engaging said first named screw and having threaded connection with the shank of said swivel pin whereby the latter is rotatably confined within said bore, and a fulcrum connection between said swivel pin and said arm.

BEN PEPPERDINE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 539,012 Smith May 7, 1895 1,125,945 Boling Jan. 26, 1915 1,161,526 Porter Nov. 23, 1915 1,453,854 Parker May 1, 1923 1,641,153 Butt Sept. 6, 1927 1,851,771 Keith Mar. 29, 1932 1,959,587 Lawson May 22, 1934 2,269,308 Gates Jan. 6, 1942 

